Alzheimer's disease is characterized by a gradual loss of memory, decline in the ability to perform routine tasks, disorientation, difficulty in learning, loss of language skills, impaired judgment and ability to plan, and personality changes. Over time, these changes become so severe that they interfere with an individual's daily functioning, resulting eventually in death. Alzheimer's disease is a type of dementia and it is only confirmed upon autopsy when the characteristic plaques and tangles are observed.
Biomarkers that can be used to diagnose Alzheimer's disease and/or other forms of dementia are in demand. Particularly useful are biomarkers that can diagnose Alzheimer's disease with greater than 95% precision and accuracy before autopsy, biomarkers that can distinguish among various forms of dementia, biomarkers that reflect modulation of the disease by therapeutics, and biomarkers that predict the progression of Alzheimer's disease well in advance of neurological symptoms. For example, studies suggest that by the time Aβ 42 or tau are altered in abundance in cerebral spinal fluid, there is already significant neuronal damage in the brain. The hope is that early stage biomarkers can be found to justify prophylactic intervention early in a patient's life.